Use-cases for reflection

Question

Recently I was talking to a co-worker about C++ and lamented that there was no way to take a string with the name of a class field and extract the field with that name; in o

Answer 1

I find reflection very useful if the input data (like xml) has a complex structure which is easily mapped to object-instances or i need some kind of "is a" relationship between the instances.

As reflection is relatively easy in java, I sometimes use it for simple data (key-value maps) where I have a small fixed set of keys. One one hand it's simple to determine if a key is valid (if the class has a setter setKey(String data)), on the other hand i can change the type of the (textual) input data and hide the transformation (e.g simple cast to int in getKey()), so the rest of the application can rely on correctly typed data. If the type of some key-value-pair changes for one object (e.g. form int to float), i only have to change it in the data-object and its users but don't have to keep in mind to check the parser too. This might not be a sensible approach, if performance is an issue...